1. Technical Field
The present invention relates to a method for determining an axial direction of a bore of a bone fixator. More particularly, the present invention relates to such a method for use in an orthopedic surgery.
2. Description of Related Art
It is common practice in the medical treatment to examine the anatomic structures of a human body by means of radiography. This is especially true for orthopedic surgeries, in which it is often necessary to know the real-time condition of a surgical instrument inside the patient's body. A C-arm X-ray machine (hereinafter referred to as C-arm for short) is now extensively used for the task.
A C-arm can show in real time the condition of a surgical instrument or an implant in a human body, so as for a surgeon to decide how a surgical operation should proceed. For example, C-arm images enable a surgeon to know how an intramedullary nail is driven into a bone and how the bores of the intramedullary nail are oriented, before locking screws can be respectively screwed into the bores to secure the intramedullary nail in the bone.
In order to screw a locking screw into a bore of an intramedullary nail, it is conventionally required to take X-ray images of the bore with a C-arm repeatedly so that the relative positions of the bore and a drill bit can be closely observed, ensuring that the drill bit is driven into the bore of the intramedullary nail in the correct direction. The repeated image-taking process, however, subjects the patient, the surgeon, and all the other medical personnel to significant X-ray exposure.
Moreover, as the direction and position of the C-arm need repeated adjustment, and X-ray images must be taken on a regular basis, the duration of the surgical operation will be lengthened. This not only increases the patient's chance of infection but also is physically demanding for the medical personnel. More importantly, the aforesaid conventional approach does not guarantee that a locking screw will be screwed into the intended bore successfully. Therefore, it is imperative to have a method for automatically determining an axial direction of a bore and thereby minimizing the exposure of radiation.